1. Field of the Invention
The present invention generally relates to protective eyewear, and more particularly to inexpensive protective eyewear having a brow bar molded with a flexible hinge to a temple piece and a unitary lens attachable for easy assembly by the purchaser without tools to the brow bar.
2. Description of Related Art
Most eyeglasses or spectacles manufactured today include a lens supporting structure or frame to which temples are pivotally attached by means of a hinge assembly. The hinge assembly can be metal or plastic and typically comprises interleaved hinge plates with aligned apertures. The hinge plates are attached respectively to the frame and the temple of the spectacles. A vertically disposed hinge pin or screw passes through the interleaved apertures and secures the hinge plates of the frame to the hinge plates of the temple. Spectacles of this construction are inappropriate for assembly by a purchaser resulting in many independent process steps in the manufacture and assembly. For the purchaser to assemble safety spectacles for immediate use in hazardous areas on plant properties, or for use as sunglasses, it is necessary that it be possible without the need for assembly tools. This requirement forces the construction of the entire spectacle from a material which can be easily handled by hand; i.e., a plastic forming the brow and temples area of the spectacles and easily, yet securely, fastening to the lens of the spectacles.
When the spectacles are worn, the frame is supported on the nose of the wearer by a bridge piece, the lens or lenses are located in front of the eyes, and the temples extend rearwardly along the sides of the heads and may engage, with ear pieces, behind the ears of the wearer. For conventional spectacles, synthetic resin materials may be used or other materials such as wires and metals can be employed in whole or in part.
Resilient hinges, which allow the temples to open to a plane beyond their normal use, are well known and have been applied to spectacles as described in U.S. Pat. No. 5,059,017 and more particularly, in U.S. Pat. No. 3,713,732 which shows a flexible hinge integrally molded into a brow piece of a two-piece spectacles. More recently, U.S. Pat. No. 5,059,017 discloses an elastically compressible bellows-like hinge that can be temporarily coupled to the frame and temple. While the spectacle hinge assemblies described above may provide for some advantages, prior art attempts to produce a safety spectacle which is inexpensive, yet easy for the consumer to assemble into a secure eyewear, until now, was still wanting.
The prior art also discloses many transparent plastic safety spectacles or goggles having a single face piece or front protective member hinged to one piece pivotal plastic temples. For example, U.S. Pat. No. 4,271,538 discloses safety spectacles having a one piece ranged and curved front face piece adapted to wrap around the forehead to the wearers temples. However, these spectacles are formed by assembly of several independently manufactured pieces and do not lend to self-assembly. Unfortunately, when the face piece is scratched or becomes cracked, there is no practical alternative to discarding the entire spectacle and replacing it with a new one. Furthermore, the presently available eyewear, particularly low-cost protective spectacles provide mostly flat lens or curved lens in only a single plane. There exists an unsolved need for protective eyewear in which a unitary lens, particularly a spherical lens, may be easily assembled for use on the spot without the need for external tools, thus, scratched lens may be replaced with a new one or a tinted lens for functional or cosmetic reasons.
Still needed is a new two piece, easily assembled pair of glasses which are also easily molded and manufactured. The spectacles of the invention provide that advantage.